Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
  • G03F7/032—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders
  • G03F7/037—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders the binders being polyamides or polyimides
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/22—Secondary treatment of printed circuits
  • H05K3/28—Applying non-metallic protective coatings
  • H05K3/285—Permanent coating compositions
  • H05K3/287—Photosensitive compositions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
  • Y10T428/24917—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including metal layer

Definitions

• This invention relates to a photosensitive cover coating agent used for coating flexible circuit bases. More particularly, it relates to a photosensitive cover coating agent which is easily produced and superior in compatibility, sensitivity, heat resistance, flexibility, adhesion and electrical properties.
• the insulating protective coating for printed wiring board has been required for the insulating protective coating for printed wiring board to satisfy any characteristics of heat resistance sufficiently endurable to solder immersion, firm adhesion onto circuit base and electrical insulating properties, and in the case of flexible printed wiring board, it has been further required to satisfy flexibility in addition to the above-mentioned characteristics.
• cover lay film has been used as insulating protective film for printed wiring board.
• an adhesive is coated onto one side surface of polyimide or polyester film, followed by boring only a terminal-connecting part by means of punching or the like, positioning the part onto a circuit base by hand operation and adhering the film at a high temperature and under a high pressure by means of hot plate pressing.
• the resulting film is superior in the flexibility and advantageous in the aspect of circuit protection, but a problem has been raised.
• CAD design language
• the cost of mold preparation by means of CAD and the plant cost for hot plate processing become high.
• the positioning onto the wiring board becomes difficult.
• an adhesive is applied, smears are liable to occur at the time of boring process by means of drill or the like and there is a fear that the adhesive exudes out at the time of pressing.
• cover lay ink On the other hand, a process of forming an insulating protective film on the printed wiring board according to a printing method (cover lay ink) has been developed.
• a cover lay inking agent having been presently used is the one having applied a solder resist, so far used for rigid base; hence there has been a problem that the agent is inferior in the flexibility and insufficient in the heat resistance, electrical properties and adhesion onto the base.
• the reactivity of the resin is rapid, it has very often been used in a two-part form; hence its handling is cumbersome, and the pot life after mixing of the two parts is so short that a problem of storage stability has been raised.
• Japanese patent application laid-open No. Sho 55-145717 discloses a composition consisting of an epoxy acrylate resin and a melamine resin, but the composition has a disadvantage of poor flexibility.
• Japanese patent publication Nos. Sho 50-4395 and Sho 53-10636 disclose acrylic resin compositions of sulfomethylene acrylate, phosphoric acid ethylene acrylate, etc., but while any of them are relatively good in the flexibility, they are notably inferior in the heat resistance.
• the pattern dimension is limited due to positioning of the cover lay film on the wiring board, exudation of adhesive at the time of pressing, etc.
• the pattern dimension has a limitation of 100 ⁇ m, due to the positioning on the wiring board, exudation, sagging, etc. of the pattern. Such a limitation cannot correspond to pattern fining of circuit base to be required in future.
• a fining process by means of a lithography process using a photosensitive material is a technique capable of sufficiently corresponding to pattern fining of circuit base.
• the photosensitive material includes highly heat-resistant, photosenstive polyimides. Most of these polyimides are a material obtained by introducing a photosensitive group into a polyimide precursor or a polyimide or a material obtained by mixing a compound having a photosensitive group with a polyimide precursor.
• Japanese patent publication No. Sho 55-41422 proposes a process for preparing the polyimide by imparting a photosensitive group to the side chain of a polyamic ester
• Japanese patent laid-open No. Sho 60-6729 proposes a process for preparing the polyimide by preparing a diamine having a double bond in advance, followed by preparing the polyimide using the diamine.
• the process of introducing the functional group is complicated and a high cost is required.
• Japanese patent application laid-open Nos. Sho 55-45746 and Sho 60-100143 each propose a process of reacting an unsaturated epoxy compound or a double bond-containing isocyanate compound with the carboxyl group of a polyamic acid, but the process has a drawback that when the unsaturated group-containing compound is reacted with the carboxyl group of the polyamic acid, a portion of the polyamic acid decomposes to lower the solution viscosity.
• Japanese patent application laid-open Nos. Sho 63-206741, Sho 59-15449 and Hei 2-144539 propose a composition obtained by mixing a polyamic acid with a photoreactive, unsaturated group-containing compound, but since such unsaturated group-containing compounds are usually inferior in the compatibility with polyamic acid, practically the use conditions and the kinds of the unsaturated group-containing compound or polyamic acid are restricted; hence the above compounds are diffcultly used.
• a photosensitive cover coating agent consisting of a polyamic acid mentioned below, a specified polyfunctional monomer and a photopolymerization initiator or a sensitizing agent is superior in the compatibility, sensitivity, heat resistance, adhesion, electrical properties and flexibility.
• the object of the present invention is to provide a photosensitive cover coating agent forming an insulating protective coating superior in the compatibility, sensitivity, heat resistance, adhesion, electrical properties and flexibility.
• the present invention consists in a photosensitive cover coating agent obtained by mixing a polymer (A) comprising repeating units of the formula (I) wherein R1 represents and and R2 represents an aromatic and/or aliphatic hydrocarbyl group optionally interrupted with one or more of oxygen atoms, sulphur atoms, sulfone groups or silane groups; a compound (B) having two or more acryloyl groups or methacryloyl groups in one molecule which is an acrylate or methacrylate of a polyhydric aromatic and/or aliphatic alcohol optionally interrupted with one or more oxygen atoms; and a compound (C) of the formula (II) wherein Z represents a divalent aliphatic group or alicyclic group, R3 represents a hydrogen atom, or a hydroxyl, carboxyl, amide or nitrile group, or an aliphatic, alicyclic, aromatic or araliphatic group containing from 1 to 10 carbon atoms and optionally containing
• the polyamic acid used in the photosensitive cover coating agent of the present invention is obtained by reacting an organic tetracarboxylic dianhydride with an organic diamine, and the reaction is usually carried out in an organic solvent.
• the reaction of obtaining the polyamic acid is an exothermic reaction, and it is preferable to control the reaction under cooling, if necessary. Further, there is also preferable a process of suspending or dissolving either one of a tetracarboxylic anhydride and a diamine in an organic solvent, followed by reacting while adding the otehr, and even if either one of the two components is used in an excess quantity within a range of 10:9 to 9:10, there is no problem.
• the tetracarboxylic dianhydride is expressed by the formula (III) wherein R1 represents and used alone or in a combination of two kinds or more thereof.
• diamines such as 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-di(m-aminophenoxy)diphenyl sulfone, 4,4'-di(p-aminophenoxy)diphenyl sulfone, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, benzidine, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl-2,2-propane, 1,5-diaminonaphthalene
• aromatic diamines such as 4,4'-diaminodiphen
• Examples of the solvent used for the reaction of the tetracarboxylic dianhydride with the diamine to form the polyamic acid are N,N-dimethylformamide, N,N-diethylformamide, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N-methylcaprolactam, dimethyl sulfoxide, hexamethylphosphoamide, tetramethylenesulfone, tetramethylurea, ⁇ -butyrolactone, N-acetyl-2-pyrrolidone, phenol, cresols, nitro compounds, chlorine solvents such as chloroform, methylene chloride, etc., cellosolves, carbitols, etc.
• a general-purpose solvent such as benzene, toluene, xylene, etc. may be added to the above solvents.
• an aminosilane expressed by the formula H 2 N - R5 - S i R6 3 - k Y k wherein R5 represents -(CH 2)s -, -(CH2) s -(phenylene group)-(CH2) s -o-(phenylene group)- or -(phenylene group)-wherein s represents an integer of 1 to 4, R6 independently represents an alkyl group of 1 to 6 carbon atoms, phenyl group or an alkyl-substituted phenyl group of 7 to 12 carbon atoms, Y independently represents a hydrolyzable alkoxy group, an acetoxy group or a halogen atom and k has a value of 1 ⁇ k ⁇ 3.
• aminosilane examples include the following known compounds, but it is not always limited these examples: aminomethyl-di-n-propoxy-methylsilane, ( ⁇ -aminoethyl)-n-propoxy-methylsilane, ( ⁇ -aminoethyl)-diethoxy-phenylsilane, ( ⁇ -aminoethyl)-tri-n-propoxysilane, ( ⁇ -aminoethyl)-dimethoxy-methylsilane, ( ⁇ -aminopropyl)-di-n-propoxy-methylsilane, ( ⁇ -aminopropyl)-di-n-butoxy-methylsilane, ( ⁇ -aminopropyl)-triethoxysilane, ( ⁇ -aminopropyl)-di-n-pentoxy-phenylsilane, ( ⁇ -aminopropyl)-methoxy-n-propoxy-methylsilane, ( ⁇ -aminobuty
• the viscosity of the resulting polymer it is preferred to adjust the viscosity to a viscosity of 500 to 100,000 cp., preferably 5,000 to 50,000 cp. as measured by E type viscometer (Rotar 3°xR14).
• the other parts than acryloyl groups or methacryloyl groups are not particularly limited, and compounds having various structures may be used. Most of them are easily obtained as commercially available products.
• the preferable number of acryloyl groups or methacryloyl groups is 4 or less, more preferably 2, in one molecule.
• Z in the formula (II) is analiphatic group or an alicyclic group and the number of carbon number is preferably 1 to 10.
• R3 is a hydrogen atom or an aliphatic group, an alicyclic group, an aromatic group or an araliphatic group of 1 to 10 carbon atoms which may be substituted with one or more of unsaturated bonds or hydroxyl, carboxyl, ether, amide, ester or ketone group.
• the group R3 is hydrogen or a hydroxyl, carboxyl amide or nitrile group.
• R4 is a hydrogen atom or -Z-R3.
• R4 is a hydrogen atom, a product having a higher sensitivity is obtained; hence R4 is preferably a hydrogen atom.
• Examples of the compound (C) expressed by the formula (II) are the following amino compounds, but it is not limited to the examples: H2 N - C H2 C H2 C H3, H2 N - C H2 C H2 C H2 C H3, H2 N - C H2 C H2 C H2 C H2 C H3 H2 N - C H2 -O H, H2 N - C H2 C H2 - O H H2 N - C H2 C H2 C H2 C H2 - O H H2 N - C H2 C H2 O C H2 C H2 - O H H2 N - C H2 C H2 C H2 C H2- C O O H
• the quantity of the compound (C) added is 0.01 to 0.80 molar equivalent based upon the compound (B). If it is less than 0.01 molar equivalent, the compatibility of the polyamic acid with the compound having acryloyl groups or methacryloyl groups is inferior and the sensitivity is low. If it exceeds 0.50 molar equivalent, the developing properties, the sensitivity and the stability of the photosensitive cover coating agent with lapse of time become inferior. Further, the total quantity of the compound (B) and the compound (C) is 20 to 200 parts by weight based upon 100 parts by weight of the polymer (A). If the quantity is less than 20 parts by weight, the sensitibity is low, while if it exceeds 200 parts by weight, the quality of the polyimide film as the final product becomes inferior.
• the compound having acryloyl groups or methacryloyl groups and the amino compound are mixed in the polyamic acid solution, or they are mixed in a solvent or without any solvent in advance, followed by adding to and mixing with the polyamic acid solution. At that time, heat generation often occurs; thus, in order to prevent decomposition of the polyamic acid and thermal polymerization of the compound having acryloyl groups or methacryloyl groups, cooling down to 70°C or lower is preferred.
• the photopolymerization initiator or sensitizer (D) the following compounds may be used alone or in admixture: benzophenone, Michler's ketone, 4,4'-diethylaminobenzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, isopropylbenzoin ether, isobutylbenzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, benzyl, camphorquinone, benzanthrone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propane, 3,3'
• the quantity of the photopolymerization initiator or sensitizer added is 0.05 to 20 parts by weight based upon 100 parts by weight of the polymer. If it is less than 0.05 part by weight, its effect is poor, while if it exceeds 20 parts by weight, the film quality becomes inferior. Its preferable quantity added is 0.5 to 10 parts by weight.
• Examples of such a compound are as follows: butyl acrylate, cyclohexyl acrylate, dimethylamino-ethyl methacrylate, benzyl acrylate, carbitol acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, N-methylolacrylamide, diacetone acrylamide, N-vinylpyrrolidone, etc.
• a bisazido compound such as 2,6-bis(p-azidobenzylidene)-cyclohexanone, 2,6-bis(p-azidobenzylidene)-4-methylcyclohexanone, 2,6-bis(p-azidobenzylidene)-4-tert-butylcyclohexane, etc. to 100 parts by weight of the polymer (A).
• the photosensitive cover coating agent of the present invention is obtained.
• the photosensitive cover coating agent of the present invention is usually applied in the form of a solution.
• the solution is coated onto the total surface of the printed circuit base according to a known method such as roll coating method, doctor knife method, comma coater method, spray coating method, screen printing method, etc., followed by baking the resulting material in an oven to remove most of the solvent in the coating.
• a negative mask is put on the coating, followed by irradiation with chemical rays.
• chemical rays are X-rays, electronic rays, ultraviolet rays, visible rays, etc., and ultraviolet rays are particularly preferable.
• an aqueous solution of NaOH, KOH, Na2CO3, tetramethylammonium hydroxide, trimethylhydroxyethyl ammonium hydroxide or the like is usable, and if necessary, an alcohol, a surfactant or the like is further added to the above.
• the finally obtained pattern is baked at 200° to 250°C to afford the objective insulating protective coating of a printed wiring board having superior heat resistance, flexibility, adhesion, electrical properties, etc.
• a 2 l capacity, four-neck, separable flask provided with a stirrer, a thermometer and a nitrogen gas-purging means was fixed on a water bath.
• To this flask was added dehydrated and purified N-methyl-2-pyrrolidone (600 ml) in a nitrogen gas current. Further, to the flask was added 4,4'-diaminodiphenyl ether (60.46 g, 302.0 mmol), followed by suspending and dissolving together.
• pyromellitic dianhydride 65.87 g, 302.0 mmol
• the thus obtained polyamic acid solution had a viscosity of 39,000 cp as measured under conditions of a solids concentration of 17% by weight and an E type viscometer: rotor 3°xR14, 20 rpm (hereinafter this viscometer being employed).
• the thus obtained polyamic acid solution had a solids concentration of 16% by weight and a viscosity of 12,000 cp as measured by the E type viscometer.
• the thus obtained polyamic acid solution had a solids concentration of 15% by weight and a viscosity of 25,000 cp as measured by the E type viscometer.
• the thus obtained polyamic acid solution had a solids concentration of 20% by weight and a viscosity of 9,000 cp as measured by the E type viscometer.
• the thus obtained polyamic acid solution had a solids concentration of 15% by weight and a viscosity of 50,000 cp as measured by the E type viscometer.
• Polyethylene glycol 400 diacrylate (PEG-400DA, trade name of product made by Nihon Kayaku Co., Ltd.) (100 g) and ethanolamine (4.0 g) were mixed with stirring at 30°C, for one hour, followed by mixing the polyamic acid solution (100 g) obtained in Reference example 1, the mixed solution (17 g) obtained above, Michler's ketone (0.85 g) and 2,4-diethylthioxanthone (Kayacure-DETX, trademark of product made by Nihon Kayaku Co., Ltd.) (0.85 g), with stirring and dissolving them together, to obtain the photosensitive cover coating agent of the present invention.
• PEG-400DA Polyethylene glycol 400 diacrylate
• ethanolamine 4.0 g
• the thus obtained solution was coated onto a flexible copper-lined sheet (a polyimide base of 30 ⁇ m thick) by means of Baker's applicator, followed by heat-treating the resulting sheet in an oven at 100°C for 10 minutes and then subjecting the heat-treated sheet to exposure to ultraviolet light by means of a mercury lamp, vacuum, both surfaces-exposing machine (MPL-S, trade name of product made by Print Denshi Sogyo Co., Ltd.) fitted with a high pressure mercury lamp (HL-10201 BF, trade name of product made by Ushio Denki Co., Ltd.), through a test photomask.
• MPL-S both surfaces-exposing machine
• HL-10201 BF high pressure mercury lamp
• the resulting material was developed with a 5% Na2CO3 aqueous solution for one minute, followed by rinsing it with purified water for one minute, drying in an oven at 100°C for 10 minutes, further elevating the temperature up to 240°C to carry out heat treatment for 30 minutes.
• the resulting coating was subjected to measurements of coating thickness before the development, developing properties, sensitivity, heat resistance, flexibility, adhesion and electrical properties. The results are shown in Table 1.
• the conductor pattern of the flexible copper-lined sheet (polyimide base thickness: 60 ⁇ m) having no coating a conductor pattern having formed a conductor in one reciprocation of a conductor width of 1.5 mm and a clearance of 1.0 mm, by etching, was used.
• a conductor pattern of the flexible copper-lined sheet having a coating a conductor pattern having formed a cover coating film on the conductor pattern of the flexible copper-lined sheet having no coating was used.
• the heat resistance when the coating was floated on a solder bath at 280°C for 60 seconds, the peeling, buldge and discoloration of the coating were judged by naked eyes, and a coating having no change observed between before and after the test was regarded as good, while a coating having any change observed was regarded as inferior.
• the adhesion was evaluated based upon JIS K 5400 and according to the judgement standards of Japan Paint Engineering Association (Foundation). Namely, a section of 1 cm square was divided by lines each having an interval of 1 mm longitudinally and laterally, and only the coating was cut by means of a cutter knife so as to give 100 sections of 1 mm square along these lines and nicks wrere provided so that the base could not be cut. Next, a cellophane tape was applied onto the nicked coating, followed by pulling up the tape at an angle of 90°, and evaluating the adhesion by counting what number of the sections of 1 mm square were peeled off at that time. A coating without any peeling and any deficit in the respective sections was regarded as good, while a coating having one or more peelings and having a deficit was regarded as inferior.
• EO-modified bisphenol F diacrylate (Kayarad R-712, trademark of product made by Nihon Kayaku Co., Ltd.) (12.95 g) and n-butylamine (0.65 g) were added to the polyamic acid solution (100 g) obtained in Reference example 1, followed by mixing them with stirring at 30°C for 2 hours, further adding Michler's ketone (0.31 g) and 2,2-dimethoxy-2-phenylacetophenone (1.53 g) and mixing them and dissolving together to obtain a photosensitive cover coating agent of the present invention.
• Oligo ester diacrylate (M-6100, trade name of product made by Toa Gosei Kagaku Kogyo Co., Ltd.) (100 g) and ethanolamine (4.0 g) were mixed with stirring at 30°C for one hour, followed by mixing, agitating and dissolving together the polyamic acid solution (100 g) obtained in Reference example 2, the above-mentioned mixed solution (16 g), 3,3',4,4'-tetra(t-butylperoxycarbonylbenzophenone (BTTB, trade name of product made by Nihon Yushi Co., Ltd.) (0.8 g) and 2,4-diethylthioxanthone (Kayacure-DETX, trademark of product made by Nihon Kayaku Co., Ltd.) (0.80 g) to obtain a photosensitive cover coating agent of the present invention.
• BTTB 3,3',4,4'-tetra(t-butylperoxycarbonylbenzophenone
• BTTB
• Neopentyl glycol-modified trimethylolpropane diacrylate (R-604, trade name of product made by Nihon Kayaku Co., Ltd.) (80 g), pentaerythritol triacrylate (made by Kokusan Kagakusha Co., Ltd.) (20 g) and ethanolamine (5 g) were mixed with stirring at 30°C for one hour, followed by mixing, agitating and dissolving together the polyamic acid solution (100 g) obtained in Reference example 3, the above-mentioned mixed solution (15 g), isopropylthioxanthone (Quantacure-ITX, trademark of product made by Ward Blenkinsop Co., Ltd.) (0.60 g) and 2-methyl-1-[4-methylthio)phenyl]-2-morpholino-1-propane (Irgacure-907, trademark of product made by Ciba Geigy Co., Ltd.) (0.60 g) to obtain a photosensitive cover coating agent
• Polyethylene glycol 400 diacrylate (PEG-400DA, trade name of product made by Nihon Kayaku Co., Ltd.) (9.43 g), oligo ester diacrylate (M-6100, trade name of product made by Toa Gosei Kagaku Co., Ltd.) (9.43 g) and 1-amino-2-propanol (1.14 g) were added to the polyamic acid solution (100 g) obtained in Reference example 4, followed by mixing them with stirring at 30°C for 2 hours and further adding, mixing and dissolving together Michler's ketone (1.0 g) and 2,4-diethylthioxanthone (1.0 g) to obtain a photosensitive cover coating agent of the present invention.
• PEG-400DA trade name of product made by Nihon Kayaku Co., Ltd.
• M-6100 trade name of product made by Toa Gosei Kagaku Co., Ltd.
• Polyethylene glycol 400 diacrylate (PEG-400DA, trade name of product made by Nihon Kayaku Co., Ltd.) (100 g) and ethanolamine (4.0 g) were mixed with stirring at 30°C for one hour, followed by mixing, agitating and dissolving together the polyamic acid solution (100 g) obtained in Reference example 5, the above-mentioned mixed solution (15 g), Michler's ketone (0.75 g) and 2,4-diethylthioxanthone (Kayacure-DETX, trademark of product made by Nihon Kayaku Co., Ltd.) (0.75 g) to obtain a photosensitive cover coating agent.
• PEG-400DA trade name of product made by Nihon Kayaku Co., Ltd.
• Example 1 Measurements were carried out as in Example 1. As a result, the developing properties were inferior and there was a residual coating at the unexposed part.
• EO-modified bisphenol F diacrylate (Kayarad R-712, trademark of product made by Nihon Kayaku Co., Ltd.) (16.0 g), Michler's ketone (0.8 g) and 2,2-dimethoxy-2-phenylacetophenone (0.8 g) were added to the polyamic acid solution (100 g) obtained in Reference example 2, followed by mixing them and dissolving together to obtain a photosensitive cover coating agent.
• Dimethylaminoethyl methacrylate (13.50 g), Michler's ketone (0.76 g) and 2,4-diethylxanthone (kayacure-DETX, trademark of product made by Nihon Kayaku Co., Ltd.) (0.76 g) were mixed with the polyamic acid solution (100 g) obtained in Reference example 1, followed by agitating the mixture and dissolving together to obtain a photosensitive cover coating agent.
• the photosensitive cover coating agent of the present invention can be easily prepared using cheap materials, and is superior in the compatibility of the materials with one other, sensitivity, heat resistance, flexibility, adhesion and electrical properties; hence it is very useful as an insulating protective coating for flexible circuit bases.

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• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Paints Or Removers (AREA)
• Non-Metallic Protective Coatings For Printed Circuits (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1991
  • 1991-12-09 JP JP03350325A patent/JP3084585B2/ja not_active Expired - Lifetime
• 1992
  • 1992-11-23 US US07/980,164 patent/US5326792A/en not_active Expired - Lifetime
  • 1992-12-09 DE DE69222276T patent/DE69222276T2/de not_active Expired - Fee Related
  • 1992-12-09 EP EP92311220A patent/EP0546814B1/de not_active Expired - Lifetime

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